The Collaborative International Dictionary of English v.0.48:

Apeak \A*peak"\, adv. & a. [Pref. a- + peak. Cf. F. [`a] pic
   vertically.] (Naut.)
   In a vertical line. The anchor in apeak, when the cable has
   been sufficiently hove in to bring the ship over it, and the
   ship is them said to be hove apeak. [Spelt also apeek.]
   [1913 Webster]